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The British Journal of Radiology Jan 2023High resolution ultrasound (US) and magnetic resonance (MR) neurography are both imaging modalities that are commonly used for assessing peripheral nerves including the... (Review)
Review
High resolution ultrasound (US) and magnetic resonance (MR) neurography are both imaging modalities that are commonly used for assessing peripheral nerves including the sural nerve (SN). The SN is a cutaneous sensory nerve which innervates the lateral ankle and foot to the base of the fifth metatarsal. It is formed by contributing nerves from the tibial and common peroneal nerves with six patterns and multiple subtypes described in literature. In addition to the SN being a cutaneous sensory nerve, the superficial location enables the nerve to be easily biopsied and harvested for a nerve graft, as well as increasing the susceptibility to traumatic injury. As with any peripheral nerves, pathologies such as peripheral nerve sheath tumors and neuropathies can also affect the SN. By utilizing a high frequency probe in US and high-resolution MR neurography, the SN can be easily identified even with the multiple variations given the standard distal course. US and MRI are also useful in determining pathology of the SN given the specific image findings that are seen with peripheral nerves. In this review, we evaluate the normal imaging anatomy of the SN and discuss common pathologies identified on imaging.
Topics: Humans; Sural Nerve; Peroneal Nerve; Ankle; Lower Extremity; Ankle Joint; Magnetic Resonance Imaging
PubMed: 36039944
DOI: 10.1259/bjr.20220336 -
Muscle & Nerve Aug 2021After initial investigation of patients presenting with symptoms suggestive of neuropathy, a clinical decision is made for a minority of patients to undergo further... (Review)
Review
After initial investigation of patients presenting with symptoms suggestive of neuropathy, a clinical decision is made for a minority of patients to undergo further assessment with nerve biopsy. Many nerve biopsies do not demonstrate a definitive pathological diagnosis and there is considerable cost and morbidity associated with the procedure. This highlights the need for appropriate selection of patients, nerves and neuropathology techniques. Additionally, concomitant muscle and skin biopsies may improve the diagnostic yield in some cases. Several advances have been made in diagnostics in recent years, particularly in genomics. The indications for nerve biopsy have consequently changed over time. This review explores the current indications for nerve biopsies and some of the issues surrounding its use. Also included are comments on alternative diagnostic modalities that may help to supplant or reduce the use of nerve biopsy as a diagnostic test. These primarily include extraneural biopsy and neuroimaging techniques such as magnetic resonance neurography and nerve ultrasound. Finally, we propose an algorithm to assist in deciding when to perform nerve biopsies.
Topics: Humans; Muscle, Skeletal; Nerve Tissue; Neurosurgical Procedures; Peripheral Nervous System Diseases; Skin; Sural Nerve
PubMed: 33629393
DOI: 10.1002/mus.27201 -
PloS One 2022The objective was to analyze the clinical characteristics and pathological characteristics of sural biopsy in nitrous oxide (N2O) -induced peripheral neuropathy.
OBJECTIVE
The objective was to analyze the clinical characteristics and pathological characteristics of sural biopsy in nitrous oxide (N2O) -induced peripheral neuropathy.
METHODS
We recruited 18 patients with N2O abuse-induced neurological disorders and reported their demographic data, clinical manifestations, laboratory examinations, and nerve conduction studies. Seven patients underwent sural nerve biopsy pathologic examination.
RESULTS
All 18 patients had polyneuropathy, the nerve conduction results showed significant reductions in motor and sensory amplitudes, slowing of conduction velocities, and prolongation of latencies in most tested nerves compared to the controls. Toluidine blue staining of semi-thin sections of sural nerve biopsy showed decreased myelinated nerve fiber density, increased thin myelinated nerve fiber density, and axonal regeneration. Electron microscopy showed axonal degeneration and nerve regeneration.
CONCLUSION
The main manifestations of peripheral nerve damage caused by the abuse of N2O are lower limb weakness and distal sensory disorder. The nerve conduction study results demonstrated that mixed axonal and demyelinating neuropathy was the most common type of neuropathy. Sural biopsy showed the main pathological change was chronic axonal degeneration.
Topics: Biopsy; Humans; Nitrous Oxide; Peripheral Nerve Injuries; Polyneuropathies; Sural Nerve; Tolonium Chloride
PubMed: 36112660
DOI: 10.1371/journal.pone.0274765 -
Reumatologia Clinica 2020One of the missions of the Spanish Society of Rheumatology is to provide the necessary tools for excellence in health care. Currently, there is no reference point to...
INTRODUCTION
One of the missions of the Spanish Society of Rheumatology is to provide the necessary tools for excellence in health care. Currently, there is no reference point to quantify medical actions in this specialty, and this is imperative.
MATERIAL AND METHOD
A list of actions was drawn up and a hierarchical classification system was established by developing a complexity index, calculated based on the completion time and difficulty level of each action.
RESULTS
The results of the Delphi method tended to the consensus opinion within a group (mean σ2 - σ1=0.75-1.43=-0.68, mean IQR2 - IQR1=0.8-1.9=-1.1). The values of the complexity index ranged between 48 and 465 points. Among consultation actions, those reaching the highest scores were the first inpatient visit (366) and visits to the patient's home (369). Among diagnostic techniques, biopsies were prominent, those with the highest score were: bone biopsy (465), sural nerve biopsy (416) and synovial biopsy (380). Ultrasound scan scored 204, capillaroscopy 113 and densitometry 112. Among therapeutic techniques, infiltration/ arthrocentesis/articular injection in children reached the highest difficulty (388). The score for ultrasound-guided articular injection was 163. The score for clinical report on disability was 323 and expert report 370.
CONCLUSIONS
A nomenclature of 54 actions in Rheumatology was compiled. Biopsies (bone, sural nerve, synovial), inpatient visits, visits to the patient's home, infiltrations in children, and the preparation of the expert report were identified as the most complex actions. Musculoskeletal ultrasound is twice as complex as subsequent visits, capillaroscopy or bone densitometry.
Topics: Arthrocentesis; Biopsy; Bone and Bones; Delphi Technique; Densitometry; House Calls; Humans; Injections, Intra-Articular; Inpatients; Microscopic Angioscopy; Rheumatology; Sural Nerve; Synovial Membrane; Time Factors; Ultrasonography
PubMed: 30745278
DOI: 10.1016/j.reuma.2018.11.010 -
Journal of Neurology, Neurosurgery, and... Apr 1988A case of sensory perineuritis is described, affecting individual cutaneous nerves in the extremities and with a chronic inflammatory exudate confined to the perineurium...
A case of sensory perineuritis is described, affecting individual cutaneous nerves in the extremities and with a chronic inflammatory exudate confined to the perineurium in a sural nerve biopsy. No cause was found. The condition slowly resolved on steroid treatment.
Topics: Axons; Biopsy; Female; Foot; Hand; Humans; Microscopy, Electron; Middle Aged; Nerve Degeneration; Nerve Fibers, Myelinated; Neuritis; Sensation; Sural Nerve
PubMed: 3379419
DOI: 10.1136/jnnp.51.4.473 -
Turkish Journal of Medical Sciences Apr 2021The aim of the present study was to determine the course and possible variations of the sural nerve with all anatomical details in human fetal cadavers.
BACKGROUND/AIM
The aim of the present study was to determine the course and possible variations of the sural nerve with all anatomical details in human fetal cadavers.
MATERIALS AND METHODS
This study was performed on 60 fetal cadavers. Formation type and level of the sural nerve was detected.
RESULTS
According to trimesters, it was determined that the mean transverse and vertical distance between the lowest point of the LM and the SN varied between 1.1 and 2.9 mm and 1.54 and 3.58 mm, respectively. Type 2 was the most common seen type of sural nerve (35.83%). It was determined that the sural nerve was mostly formed at the middle third of the leg (42.5%).
CONCLUSION
Sural nerve graft with the knowledge of the anatomical details may be used for peripheral nerve reconstruction is required in congenital lesions, such as facial paralysis, obstetric brachial paralysis, and posttraumatic lesions in infants and children.
Topics: Cadaver; Child; Dissection; Female; Fetus; Gestational Age; Humans; Infant; Leg; Male; Peripheral Nerve Injuries; Pregnancy; Pregnancy Trimesters; Plastic Surgery Procedures; Sural Nerve
PubMed: 32718120
DOI: 10.3906/sag-2005-225 -
Journal of Neurophysiology May 2014Intact and injured cutaneous C-fibers in the rat sural nerve are cold sensitive, heat sensitive, and/or mechanosensitive. Cold-sensitive fibers are either low-threshold...
Intact and injured cutaneous C-fibers in the rat sural nerve are cold sensitive, heat sensitive, and/or mechanosensitive. Cold-sensitive fibers are either low-threshold type 1 cold sensitive or high-threshold type 2 cold sensitive. The hypothesis was tested, in intact and injured afferent nerve fibers, that low-threshold cold-sensitive afferent nerve fibers are activated by the transient receptor potential melastatin 8 (TRPM8) agonist menthol, whereas high-threshold cold-sensitive C-fibers and cold-insensitive afferent nerve fibers are menthol insensitive. In anesthetized rats, activity was recorded from afferent nerve fibers in strands isolated from the sural nerve, which was either intact or crushed 6-12 days before the experiment distal to the recording site. In all, 77 functionally identified afferent C-fibers (30 intact fibers, 47 injured fibers) and 34 functionally characterized A-fibers (11 intact fibers, 23 injured fibers) were tested for their responses to menthol applied to their receptive fields either in the skin (10 or 20%) or in the nerve (4 or 8 mM). Menthol activated all intact (n = 12) and 90% of injured (n = 20/22) type 1 cold-sensitive C-fibers; it activated no intact type 2 cold-sensitive C-fibers (n = 7) and 1/11 injured type 2 cold-sensitive C-fibers. Neither intact nor injured heat- and/or mechanosensitive cold-insensitive C-fibers (n = 25) and almost no A-fibers (n = 2/34) were activated by menthol. These results strongly argue that cutaneous type 1 cold-sensitive afferent fibers are nonnociceptive cold fibers that use the TRPM8 transduction channel.
Topics: Anesthesia; Animals; Cold Temperature; Electric Stimulation; Hot Temperature; Male; Menthol; Microelectrodes; Neurons, Afferent; Peripheral Nervous System Agents; Physical Stimulation; Rats, Wistar; Skin Physiological Phenomena; Sural Nerve; TRPM Cation Channels; Thermosensing
PubMed: 24572095
DOI: 10.1152/jn.00287.2013 -
PloS One 2022Regeneration after severe peripheral nerve injury is often poor. Knowledge of human nerve regeneration and the growth microenvironment is greatly lacking. We aimed to...
Regeneration after severe peripheral nerve injury is often poor. Knowledge of human nerve regeneration and the growth microenvironment is greatly lacking. We aimed to identify the regenerative proteins in human peripheral nerve by comparing the proteome before and after a transection injury. In a unique study design, we collected closely matched samples of naïve and injured sural nerve. Naïve and injured (two weeks after injury) samples were analyzed using mass spectrometry and immunoassays. We found significantly altered levels following the nerve injury. Mass spectrometry revealed that injury samples had 568 proteins significantly upregulated and 471 significantly downregulated compared to naïve samples (q-value ≤ 0.05 and Z ≥ |2| (log2)). We used Gene Ontology (GO) pathway overrepresentation analysis to highlight groups of proteins that were significantly upregulated or downregulated with injury-induced degeneration and regeneration. Significant protein changes in key pathways were identified including growth factor levels, Schwann cell de-differentiation, myelination downregulation, epithelial-mesenchymal transition (EMT), and axonal regeneration pathways. The proteomes of the uninjured nerve compared to the degenerating/regenerating nerve may reveal biomarkers to aid in the development of repair strategies such as infusing supplemental trophic factors and in monitoring neural tissue regeneration.
Topics: Humans; Proteome; Sural Nerve; Nerve Regeneration; Peripheral Nerve Injuries; Peripheral Nerves
PubMed: 36417411
DOI: 10.1371/journal.pone.0260998 -
Surgical anatomy of the ovine sural nerve for facial nerve regeneration and reconstruction research.Scientific Reports Jul 2019The lack of a clinically relevant animal models for research in facial nerve reconstruction is challenging. In this study, we investigated the surgical anatomy of the...
The lack of a clinically relevant animal models for research in facial nerve reconstruction is challenging. In this study, we investigated the surgical anatomy of the ovine sural nerve as a potential candidate for facial nerve reconstruction, and performed its histological quantitative analysis in comparison to the buccal branch (BB) of the facial nerve using cadaver and anesthetized sheep. The ovine sural nerve descended to the lower leg along the short saphenous vein. The length of the sural nerve was 14.3 ± 0.5 cm. The distance from the posterior edge of the lateral malleolus to the sural nerve was 7.8 ± 1.8 mm. The mean number of myelinated fibers in the sural nerve was significantly lower than that of the BB (2,311 ± 381vs. 5,022 ± 433, respectively. p = 0.003). The number of fascicles in the sural nerve was also significantly lower than in the BB (10.5 ± 1.7 vs. 21.3 ± 2.7, respectively. p = 0.007). The sural nerve was grafted to the BB with end-to-end neurorrhaphy under surgical microscopy in cadaver sheep. The surgical anatomy and the number of fascicles of the ovine sural nerve were similar of those reported in humans. The results suggest that the sural nerve can be successfully used for facial nerve reconstruction research in a clinically relevant ovine model.
Topics: Animals; Facial Nerve; Female; Nerve Regeneration; Plastic Surgery Procedures; Sheep; Sural Nerve
PubMed: 31332199
DOI: 10.1038/s41598-019-46661-3 -
Neurology India 2022Sensory nerve conduction parameters in Guillain Barre Syndrome (GBS) are underemphasized.
BACKGROUND
Sensory nerve conduction parameters in Guillain Barre Syndrome (GBS) are underemphasized.
OBJECTIVE
To describe abnormalities on sensory conduction studies in a large cohort of prospectively evaluated patients of GBS and to correlate with clinico-electrophysiological features.
METHODS AND MATERIALS
Sensory conduction parameters of three nerves (median, ulnar, and sural) were analyzed using standard protocols in 238 patients (M: F 163:75, mean age: 35.76 ± 15.9 years). Electrophysiological subtyping was based on criteria of Hadden et al., and Rajabally et al.
RESULTS
Among patients with "typical" GBS who underwent electrophysiological testing within 30 days of symptom-onset (n = 219), 183 (83.5%) had abnormal sensory potentials (one nerve = 52, two nerves = 77, all three nerves = 54). Frequency of abnormalities in sensory potentials increased with duration of illness. Commonest abnormality was reduced amplitude or in-excitable nerves. Mean amplitude and velocity of median and ulnar nerve sensory potentials were significantly lower among those with demyelinating electrophysiology (P < 0.05). Proportion of subjects with reduced amplitude and velocity of median and ulnar nerve sensory potentials was higher among those who required mechanical ventilation (P < 0.05). Frequency of "sural sparing" ranged from 10.5% to 84.5% depending on the criteria used and almost always was significantly associated with demyelinating neuropathy.
CONCLUSION
This prospective study provides comprehensive data on sensory conduction parameters in GBS. Abnormalities are frequent and vary with duration of illness. While median nerve is most frequently and more severely affected, involvement of sural nerve may have prognostic value.
Topics: Humans; Young Adult; Adult; Middle Aged; Guillain-Barre Syndrome; Prospective Studies; Sural Nerve; Neural Conduction; Respiration, Artificial
PubMed: 36537422
DOI: 10.4103/0028-3886.364073